Hypoglycemic, antidyslipidemic, hepatoprotective and antilipid peroxidation activities of hydromethanol leaf extract of Helianthus annuus in alloxan-induced diabetic rats

Purpose: To investigate the hypoglycemic, antidyslipidemic, hepatoprotective and anti-lipid peroxidation effects of hydromethanol leaf extract of Helianthus annuus (HLEHA) in alloxan-induced diabetic rats.Methods: The extract was administered once daily at 150, 300 and 600 mg/kg for 21 consecutive days. Glibenclamide (GLB) 2 mg/kg was used as a reference drug (positive control) and 5 % Tween-20 solution in water was used as negative control. The fasting blood glucose (FBG) and body weights were measured on days 7, 14 and 21 while glycosylated haemoglobin concentration (HbA1c), serum markers of liver function, lipid profile, antioxidant status, histopathological changes in pancreas and liver were determined 24 h after the last dosing on day 21.Results: The GLB and HLEHA caused significant (p < 0.05) time-dependent weight gains in the treated rats when compared with 5 % Tween-20 treated rats. The HLEHA and GLB caused significant (p < 0.05) decreases in FBG, HbA1c, malondialdehyde, and lipid profile levels in the treated rats when compared with rats in 5% tween-20 treated group. Alloxan-induced pancreatic and hepatic degeneration were reversed in GLB- and HLEHA-treated rats.Conclusion:  Helianthus annuus demonstrates potent antidiabetic, antioxidant and antidyslipidemic activities in rats.Keywords: Antidiabetic, Antidyslipidemic, Helianthus annuus, Medicinal plant, Traditional medicin

Potential antidiabetic and antioxidant activities of a heliangolide sesquiterpene lactone isolated from Helianthus annuus L. Leaves

Heliangolide is a naturally occurring sesquiterpene lactone and its derivatives are biologically active compounds present in most medicinal plants. This study evaluated the antioxidant and antidiabetic properties of a heliangolide sesquiterpene lactone isolated from Helianthus annuus L. leaves. The heliangolide sesquiterpene lactone was isolated through combination of solvent-solvent partitioning, column chromatography, thin layer chromatography and high performance-liquid chromatography techniques. The antioxidant activity of the compound was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and nitric oxide radical scavenging assays while the antidiabetic effects were investigated in alloxan-induced diabetic rats. The heliangolide derivative at 954.2 µmol L–1 showed 23.7 % DPPH and 26 % nitric oxide radical inhibitions compared with 96.6 and 50.9 %, resp., displayed by the controls (2,271.2 µmol L–1). It also reduced the fasting blood glucose (FBG) levels in a time-dependent manner. The highest activity was recorded within 6 h post-treatment at 0.2 mmol kg–1 bm. The heliangolide derivative exhibited significant (p < 0.05) antioxidant and antidiabetic properties and provides basis for further development of constituents of Helianthus annuus leaves for the management of such diseases

Effect of Chronic Administration of Hydromethanol Leaf Extract of Helianthus annuus on Erythrocytic Profile in Normal Rats

Effect of chronic administration of hydromethanol leaf extract of Helianthus annuus on erythrocytic profile in normal rat was investigated. The extract was prepared using cold maceration method and concentrated at 40°C. It was incorporated in feed at 2.5, 5 and 10 mg per 100 g feed. Albino rats were randomly assigned to 4 (A – D) groups of 14 rats each. Group A received standard feed while groups B – D received feed incorporated with H. annuus at 2.5, 5 and 10 mg/10 g feed, respectively. They were fed 10% of their body weight daily for 90 consecutive days. Blood samples were collected via retroorbital venous plexus from four rats selected at random from each group without replacement on day 30, 60 and 90 for the determination of erythrocytic profile. There was no significant (p &gt; 0.05) change on the erythrocytic profile of the various groups on day 30 and 60 while the packed cell volume and hemoglobin concentration of H. annuus treated groups were significantly (p &lt; 0.05) lower than group A rats on day 90. This study suggests that the chronic use of Helianthus annuus for up to 90 days in rat may lead to anemia and should be avoided

Acute and chronic toxicity studies of hydromethanol leaf extract of Helianthus annuus Linn. in rats

Objective: To investigate the safety levels of hydromethanol leaf extract of Helianthus annuus Linn. (H. annuus) in rat. Methods: Acute oral toxicity test of hydromethanol leaf extract of H. annuus was conducted through up and down method at 2.00 g/kg dose limit in rats. The chronic toxicity study was conducted by administering different concentrations (0.25, 0.50 and 1.00 g/ kg) of hydromethanol extract of H. annuus in feed, for 90 consecutive days. On days 30, 60 and 90, blood samples were collected from the retro-orbital plexus of the rats for determination of serum biochemical parameters. Histopathological examination of the pancreas, livers, kidneys and testis were also conducted. Results: The LD50 of the hydromethanol extract of H. annuus was greater than 2.00 g/kg and it significantly (P < 0.05) reduced serum cholesterol. On days 60 and 90, the serum urea and creatinine levels of hydromethanol extract of H. annuus treated groups were elevated when compared with the control group. There were fibrosis in the kidneys and livers; degeneration and necrosis in the testis and significant dose-dependent increases in number and size of pancreatic islet of langerhans. Conclusions: The findings suggest that hydromethanol extract of H. annuus is tolerated in short term administration, but long term (up to 90 days) administration at high doses, may elicit hepatic, testicular and nephrotic disorder